Remove project.android block from rn-tester's CLI config (facebook#35197)

Summary:
The project.android block is unnecessary and contains a wrong path. Let's use the default path which is `./android`.

## Changelog

[Internal] - Remove project.android block from rn-tester's CLI config

Pull Request resolved: facebook#35197

Test Plan: Tested locally + will wait for a CI run

Reviewed By: robhogan

Differential Revision: D41013193

Pulled By: cortinico

fbshipit-source-id: 5c76c9b571b23ad71a23a8f3f05a9acb4d6e20b9

Author: cortinico

packages/rn-tester/react-native.config.js

@@ -29,8 +29,5 @@ module.exports = {
     ios: {
       sourceDir: '.',
     },
-    android: {
-      sourceDir: '.',
-    },
   },
 };